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    <title>Document</title>
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    <script>
        // 第二题
        var m = 1;
        function f1() {
            console.log(m); // n = 1
        }
        function f3() {
            function f2() {
                f1(m);
            }

            f2();
            var m = 3;
        }
        f3();


    </script>
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